1. Field
Embodiments of the disclosure relate generally to the galley cart systems for transportation vehicles and more particularly to an automatically sealing CO2 sublimation flow system allowing flow of sublimate into cooling compartments of the galley cart through apertures with the door in the closed position and sealing the apertures with the door in the open position.
2. Background
Galley carts employed for food service in transportation vehicles such as aircraft and trains often require cooling contain food and beverages at a temperature that is cooler than a cabin of the vehicle. At least some known carts include or connect to a refrigeration system (a chiller) that provides cool air to an interior volume of the cart to cool the food/beverages. However, the chiller is powered by the vehicle systems, reducing the amount of power available to the vehicle for propulsion, thrust, etc. As such, the chiller is an inefficient draw on the power supply system of the vehicle. Further, such a chiller system adds weight and complexity to the vehicle. Accordingly, some galley carts are configured to contain dry ice that cools the food/beverages as it sublimates. One drawback with the use of dry ice is the carbon dioxide gas (CO2) sublimate that is released. The terms “CO2 gas”, “CO2 sublimate”, and the like are used to describe the gas produced by the sublimation of CO2 from solid to gas.
At least in aircraft, the Federal Aviation Administration has set forth requirements for the maximum CO2 concentration in a cabin of the aircraft. The sublimation of the dry ice may cause the CO2 concentration to exceed the maximum parts-per-million (ppm). For example, the CO2 gas may escape from the cart into the cabin when the door of the cart is opened in the galley area or in the aisle as food/beverages are served (a transient condition). Further, the CO2 gas may escape from the cart through provided leak paths to ensure that the pressure within the cart does not exceed a maximum threshold as the dry ice sublimates (a steady-state condition). Dry ice, providing CO2 gas sublimation as a coolant, is a commonly available, cost effective and volumetrically efficient refrigerant for such use. However, limiting venting of CO2 gas from the galley carts to avoid undesirable buildup of CO2 in passenger compartments is required.
It is therefore desirable to provide structurally simple and cost effective structure for control of CO2 gas sublimation in galley carts.